#!/usr/bin/env python
# -*- coding: utf-8 -*-
# author:lewsan


# def return_test(a):
#     try:
#         if a <= 0:
#             raise ValueError('data can not be negative')
#         else:
#             a = 2
#             return a
#     except ValueError as e:
#         print e
#     finally:
#         print ("The end!")
#         a = -1
#         return a
#
#
# print return_test(0)
# print return_test(2)
